Both the AMD and Intel drivers can cache not present IOTLB entries. To convert these drivers to the dma-iommu api we need a generic way to flush the NP cache. IOMMU drivers which have a NP cache can implement the .flush_np_cache function in the iommu ops struct. I will implement .flush_np_cache for both the Intel and AMD drivers in later patches.
The Intel np-cache is described here: https://software.intel.com/sites/default/files/managed/c5/15/vt-directed-io-spec.pdf#G7.66452 And the AMD np-cache is described here: https://developer.amd.com/wordpress/media/2012/10/34434-IOMMU-Rev_1.26_2-11-09.pdf#page=63 Signed-off-by: Tom Murphy <tmur...@arista.com> --- drivers/iommu/dma-iommu.c | 10 ++++++++++ include/linux/iommu.h | 3 +++ 2 files changed, 13 insertions(+) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 1a4bff3f8427..cc5da30d6e58 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -594,6 +594,9 @@ struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp, < size) goto out_free_sg; + if (domain->ops->flush_np_cache) + domain->ops->flush_np_cache(domain, iova, size); + *handle = iova; sg_free_table(&sgt); return pages; @@ -652,6 +655,10 @@ static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys, iommu_dma_free_iova(cookie, iova, size); return DMA_MAPPING_ERROR; } + + if (domain->ops->flush_np_cache) + domain->ops->flush_np_cache(domain, iova, size); + return iova + iova_off; } @@ -812,6 +819,9 @@ int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, if (iommu_map_sg_atomic(domain, iova, sg, nents, prot) < iova_len) goto out_free_iova; + if (domain->ops->flush_np_cache) + domain->ops->flush_np_cache(domain, iova, iova_len); + return __finalise_sg(dev, sg, nents, iova); out_free_iova: diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 75559918d9bd..47ff8d731d6a 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -173,6 +173,7 @@ struct iommu_resv_region { * @iotlb_sync_map: Sync mappings created recently using @map to the hardware * @iotlb_sync: Flush all queued ranges from the hardware TLBs and empty flush * queue + * @flush_np_cache: Flush the non present entry cache * @iova_to_phys: translate iova to physical address * @add_device: add device to iommu grouping * @remove_device: remove device from iommu grouping @@ -209,6 +210,8 @@ struct iommu_ops { unsigned long iova, size_t size); void (*iotlb_sync_map)(struct iommu_domain *domain); void (*iotlb_sync)(struct iommu_domain *domain); + void (*flush_np_cache)(struct iommu_domain *domain, + unsigned long iova, size_t size); phys_addr_t (*iova_to_phys)(struct iommu_domain *domain, dma_addr_t iova); int (*add_device)(struct device *dev); void (*remove_device)(struct device *dev); -- 2.17.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
